438 BOTANY AND PHARMACOGNOSY. 



PHYSOSTIGMA. CALABAR BEAN. The ripe seeds of 

 Physostigma vcncnosum (Fam. Leguminosae), a woody climber 

 growing in the region of the Gulf of Guinea on the western coast 

 of Africa (p. 298). The seeds are also known as "the ordeal 

 bean of Calabar " (Fig. 189). 



Description. Anatropous, somewhat reniform or irregularly 

 oblong or ellipsoidal, 25 to 30 mm. long, 15 to 18 mm. in diam- 



FiG. i8g. Physostigmine salicylate: orthorhombic crystals from a solution in chloroform. 



eter, 10 to 15 mm. thick, with a brownish-black groove from i to 2 

 mm. in diameter extending about half-way around the edge, con- 

 taining the raphe as a narrow line, and in which is frequently 

 found the remains of the white membranaceous funiculus, the 

 micropyle occurring near one end of the groove as a slight depres- 

 sion ; seed-coat brownish-red, hard, thick, smooth, but somewhat 

 rough near the groove ; reserve layers wanting, embryo large, 

 white, with short hypocotyl and two concavo-convex cotyledons : 

 inodorous ; taste starchy. 



